Palestinian President Mahmoud Abbas attends a swearing-in ceremony of a new Palestinian unity government Monday in the West Bank city of Ramallah, formally ending a crippling seven-year split with his Islamic militant Hamas rivals but drawing Israeli threats of retaliation.

The formation of the unity government and Israel’s tough response are part of a wider competition between Abbas and Israeli Prime Minister Benjamin Netanyahu for international support since the collapse of U.S.-led peace talks between them in April.

Abbas praised the 17-member unity government, made up of technocrats backed by Hamas and his Fatah movement, as a milestone.

“This black page in our history has been turned forever and will never come back,” he said, referring to the Palestinian split that broke open with the Hamas takeover of the Gaza Strip in 2007. For seven years, the rivals ran separate governments, with Hamas in Gaza and Abbas ruling autonomous areas of the West Bank.

Netanyahu said the new government should be shunned because it leans on support from Hamas, a group labeled as terrorist by the West. Abbas “said yes to terrorism and no to peace,” Netanyahu said after a meeting with his Security Cabinet.